Chip cards or IC (integrated circuit) cards (also commonly referred to as “smart cards”) by now are prevalently used in many applications such as for authentications, banking transactions, and payments. FIG. 1 shows a chip card 102 of a contact type according to the prior art. For such a chip card 102, a contact bank 104 and an IC (integrated circuit) chip 106 are formed onto a substrate 108 typically with a shape similar to a credit-card, according to ISO standards as known to one of ordinary skill in the art. The contact bank 104 has a plurality of contacts 110, each receiving a respective signal, such as a supply voltage, a clock signal, or data, from a contact based terminal. The IC chip 106 processes data from such signals received by the contact bank 104 after making contact with the contact based terminal.
FIG. 2 shows a chip card 112 of a contact-less type according to the prior art. For such a chip card 112, at least one antenna coil (a first antenna coil 114 and a second antenna coil 116 in the example of FIG. 2) and an IC chip 118 are formed onto a substrate 120 typically with a shape similar to a credit-card, according to ISO standards as known to one of ordinary skill in the art. The antenna coils 114 and 116 are inductively coupled to a corresponding antenna on a contact-less based terminal for transmission of signals, such as a supply voltage, a clock signal, and data. The IC chip 118 processes data from such signals received by at least one of the antenna coils 114 and 116.
A disadvantage of the chip card 102 of the contact type in FIG. 1 is that the contacts of the contact bank 104 are easily worn due to careless treatment or to frequent contact with a terminal. A disadvantage of the chip card 112 of the contact-less type in FIG. 2 is that supply power provided to the IC chip 118 via inductive coupling to the antenna coils 114 and 116 is unstable due to noise between the chip card 120 and a contact-less based terminal.
FIG. 3 shows a chip card 122 of a combined type according to the prior art. For such a chip card 122, both a contact bank 124 and at least one antenna coil (a first antenna coil 126 and a second antenna coil 128 in the example of FIG. 3) in addition to an IC chip 130 are formed onto a substrate 132 with a shape similar to a credit card, according to ISO standards as known to one of ordinary skill in the art.
FIG. 4 shows components within the IC chip 130 for the chip card 122 of the combined type in the prior art. The IC chip 130 includes a signal selection unit 134 that inputs first signals received by the contact bank 124 and second signals received by at least one of the antenna coils 126 and 128. The signal selection unit 134 selects one of such signals to be processed by a micro-computer 136 of the IC chip 130. The micro-computer 136 typically includes a data register 138 for storing data during processing by the micro-computer 136.
The signal selection unit 134 selects one of the first or second signals received by the contact bank 124 or at least one of the antenna coils 126 and 128 depending on an assigned priority. FIG. 5 shows a flowchart of steps for operation of the IC chip 130 when contact-less operation is assigned higher priority over contact operation. In that case, upon power-on (at step 140 of FIG. 5) of the IC chip 130, the signal selection unit 134 checks for availability of a RF voltage supply (RF_VDD) (at step 142 of FIG. 5). Such RF_VDD is derived from an RF signal received by at least one of the antenna coils 126 and 128.
If such RF_VDD is available (at step 142 of FIG. 5), the signal selection unit 134 selects signals received by the antenna coils 126 and 128 to be processed by the micro-computer 136. Thus, RF_VDD is selected to supply power to the micro-computer 136 (at step 144 of FIG. 5), and the data register 138 is reset (at step 146 of FIG. 5). RF data (RF_IO) derived from the RF signal received by at least one of the antenna coils 126 and 128 is then processed by the micro-computer 136 (at step 148 of FIG. 5) before power-off (at step 150 of FIG. 5) of the IC chip 130.
Further referring to FIG. 5, if RF_VDD is not available (at step 142 of FIG. 5), the signal selection unit 134 selects signals received via the contact bank 124 to be processed by the micro-computer 136. Thus, a contact voltage (CNT_VDD) received via the contact bank 124 is selected to supply power to the micro-computer 136 (at step 152 of FIG. 5), and the data register 138 is reset (at step 154 of FIG. 5). Contact data (CNT_IO) received via the contact bank 124 is then processed by the micro-computer 136 (at step 156 of FIG. 5) before power-off (at step 158 of FIG. 5) of the IC chip 130.
FIG. 5 also illustrates (outlined in dashed lines in FIG. 5) steps of operation when at least one of the antenna coils 126 and 128 receives RF signals to be processed by the micro-computer before, during, or after processing of CNT_IO (around step 156 of FIG. 5). In FIG. 5, contact-less operation is assigned higher priority over contact operation. Thus, if RF_VDD becomes available (at step 160 of FIG. 5), shortly before, during, or shortly after processing of CNT_IO (around step 156 of FIG. 5) via interrupt of (or polling by) the micro-computer 136, processing of CNT_IO (at step 156 of FIG. 5) is prematurely aborted, and steps 144, 146, 148, and 150 are performed instead to process the RF_IO.
Because the data register 136 is reset at step 146, results from previous processing of CNT_IO (at step 156 of FIG. 5) are disadvantageously lost. If RF_VDD is not available (at step 160 of FIG. 5) during such interrupt/polling, the micro-computer 136 continues with processing of CNT_IO (at step 156 of FIG. 5).
Alternatively, FIG. 6 shows a flowchart of steps for operation of the IC chip 130 when contact operation is assigned higher priority over contact-less operation. In that case, upon power-on (at step 162 of FIG. 6) of the IC chip 130, the signal selection unit 134 checks for availability of CNT_VDD from the contact bank 124 (at step 164 of FIG. 6).
If such CNT_VDD is available (at step 164 of FIG. 6), the signal selection unit 134 selects signals received by the contact bank 124 to be processed by the micro-computer 136. Thus, CNT_VDD is selected to supply power to the micro-computer 136 (at step 166 of FIG. 6), and the data register 138 is reset (at step 168 of FIG. 6). Contact data (CNT_IO) received via the contact bank 124 is then processed by the micro-computer 136 (at step 170 of FIG. 6) before power-off (at step 172 of FIG. 6) of the IC chip 130.
Further referring to FIG. 6, if CNT_VDD is not available (at step 164 of FIG. 6), the signal selection unit 134 selects signals received via at least one of the antenna coils 126 and 128 to be processed by the micro-computer 136. Thus, RF_VDD is selected to supply power to the micro-computer 136 (at step 174 of FIG. 6), and the data register 138 is reset (at step 176 of FIG. 6). In addition, RF_IO is processed by the micro-computer 136 (at step 178 of FIG. 6) before power-off (at step 180 of FIG. 6) of the IC chip 130.
FIG. 6 also illustrates (outlined in dashed lines in FIG. 6) steps of operation if the contact bank 124 receives signals to be processed by the micro-computer before, during, or after processing of RF_IO (around step 178 of FIG. 6). In FIG. 6, contact operation is assigned higher priority over contact-less operation. Thus, if CNT_VDD becomes available (at step 182 of FIG. 6), shortly before, during, or shortly after processing of RF_IO (around step 178 of FIG. 6) via interrupt of (or polling by) the micro-computer 136, processing of RF_IO (at step 178 of FIG. 6) is prematurely aborted, and steps 166, 168, 170, and 172 are performed instead to process the CNT_IO.
Because the data register 136 is reset at step 168, results from previous processing of RF_IO (at step 178 of FIG. 6) are disadvantageously lost. If CNT_VDD is not available (at step 182 of FIG. 6) during such interrupt/polling, the micro-computer 136 continues with processing of RF_IO (at step 178 of FIG. 6).
In either FIG. 5 or FIG. 6 of the prior art, processing of CNT_IO (contact data) or RF_IO (contact-less data) may be prematurely aborted, and the results of such processing are disadvantageously lost. In addition, if both RF_IO and CNT_IO are simultaneously received at the chip card 122, the micro-computer completely ignores and does not process one of RF_IO and CNT_IO depending on the assigned priority between contact and contact-less operations. However, any of such data available to the chip card may be desired to be processed for multiple functionality of the chip card.